A high-pressure pump has a plunger which reciprocates to pressurize fuel in a pressurizing chamber. JP-2008-525713A shows a high-pressure pump which has a suction passage, a pressurization chamber and a discharge passage in a housing. A cylinder supporting the plunger is provided to the housing. A suction valve and a discharge valve are provided to the housing.
WO-00-47888 (U.S. Pat. No. 6,631,706 B1) shows a high-pressure pump in which a housing an opening opposite to a pressurization chamber relative to a plunger. A cylinder is fixed in the opening of the housing. The pressurization chamber is defined between the plunger and a screw member which closes the opening of the housing.
Japanese Patent No. 4478431 shows a high-pressure pump in which a housing has an opening communicating with a pressurization chamber. A cylinder is inserted into the opening of the housing.
In order to discharge a high-pressure fuel, the housing should have an enough thickness, which makes a shape of the housing complicated and increases the weight of the housing.